Transparent display device with touch sensor

ABSTRACT

A transparent display device with a touch sensor is provided, which may reduce loss of light transmittance due to a touch sensor and a touch line, and may detect a line area, in which a defective touch sensor is included. The device includes a substrate provided with a plurality of transmissive areas and a non-transmissive area disposed between the transmissive areas adjacent to each other. The device includes a touch line extended from the non-transmissive area and connected to a touch sensor electrode, and a common power line connected to a cathode electrode to supply a cathode power source. The non-transmissive area includes a cathode power area to which the cathode power source is applied through the common power line, the cathode power area includes a first cathode power area and a second cathode power area. The second cathode power area may have resistance higher than that of the first cathode power area.

BACKGROUND Technical Field

The present disclosure relates to a transparent display device with atouch sensor.

Description of the Related Art

Recently, studies for a transparent display device in which a user mayview objects or images positioned at an opposite side through thedisplay device are actively ongoing. The transparent display deviceincludes a display area on which an image is displayed, wherein thedisplay area may include a transmissive area capable of transmittingexternal light and a non-transmissive area, and may have high lighttransmittance through the transmissive area.

A transparent display device may be provided with a plurality of touchsensors and a plurality of touch lines to implement a touch function.

BRIEF SUMMARY

The transparent display device, however, may have problems in that it isnot easy to form the plurality of touch sensors and the plurality oftouch lines or a process is complicated and light transmittance may bereduced due to the plurality of touch sensors and the plurality of touchlines. One or more embodiments of the present disclosure address thevarious technical problems in the related art and the problemsidentified above.

One or more embodiments of the present disclosure provide a transparentdisplay device that may reduce or minimize loss of light transmittancedue to a touch sensor and a touch line.

One or more embodiments of the present disclosure provide a transparentdisplay device that may detect a defective touch sensor of a pluralityof touch sensors provided in a block.

In addition to the technical benefits of the present disclosure asmentioned above, additional benefits and features of the presentdisclosure will be clearly understood by those skilled in the art fromthe following description of the present disclosure.

In accordance with an aspect of the present disclosure, the above andother objects can be accomplished by the provision of a transparentdisplay device with a touch sensor, comprising a substrate provided witha plurality of transmissive areas and a non-transmissive area disposedbetween the transmissive areas adjacent to each other, a plurality oftouch sensors respectively provided in the plurality of transmissiveareas over the substrate, including a touch sensor electrode, aplurality of pixels disposed in the non-transmissive area over thesubstrate, including an anode electrode, a light emitting layer and acathode electrode, a touch line extended in the non-transmissive area ina first direction and connected to the touch sensor electrode, and acommon power line connected to the cathode electrode to supply a cathodepower source. The non-transmissive area includes a cathode power area towhich the cathode power source is applied through the common power line,the cathode power area includes a first cathode power area disposedbetween the touch sensors adjacent to each other in a second directionand a second cathode power area disposed between the touch sensorsadjacent to each other in the first direction. The second cathode powerarea may have resistance higher than that of the first cathode powerarea.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The above and other features and other advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic plan view illustrating a transparent displaypanel;

FIG. 2 is a schematic view illustrating an example of a pixel providedin an area A of FIG. 1 ;

FIG. 3 is a view illustrating an example of signal lines, touch linesand a touch sensor, which are provided in an area B of FIG. 2 ;

FIG. 4 is a view illustrating a connection relation between a pluralityof touch blocks and a plurality of touch lines;

FIG. 5 is a view illustrating a connection relation between a pluralityof touch lines and a plurality of touch sensors in one touch block;

FIG. 6 is a cross-sectional view taken along line I-I′ of FIG. 3 ;

FIG. 7 is a cross-sectional view taken along line II-II′ of FIG. 3 ;

FIG. 8 is a cross-sectional view taken along line III-III′ of FIG. 3 ;

FIG. 9 is a view illustrating an example that a defective touch sensoroccurs in a first undercut structure due to particles;

FIG. 10 is a view illustrating an example that a high resistance area isformed in a second cathode power area;

FIG. 11 is a view illustrating another example that a high resistancearea is formed in a second cathode power area;

FIG. 12 is a cross-sectional view taken along line IV-IV′ of FIG. 11 ;

FIGS. 13A to 13C are views illustrating a current path when a defectivetouch sensor occurs;

FIG. 14 is a view illustrating luminance of a plurality of pixels when adefective touch sensor occurs;

FIG. 15 is a view illustrating an example that a defective touch sensoroccurs in one touch block; and

FIG. 16 is a graph illustrating a current per line of a plurality ofpixels provided in the touch block of FIG. 15 .

DETAILED DESCRIPTION

Advantages and features of the present disclosure, and implementationmethods thereof will be clarified through following embodimentsdescribed with reference to the accompanying drawings. The presentdisclosure may, however, be embodied in different forms and should notbe construed as limited to the embodiments set forth herein. Rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the present disclosureto those skilled in the art.

A shape, a size, a dimension (e.g., length, width, height, thickness,radius, diameter, area, etc.), a ratio, an angle, and a number ofelements disclosed in the drawings for describing embodiments of thepresent disclosure are merely an example, and thus, the presentdisclosure is not limited to the illustrated details.

A dimension including size and a thickness of each component illustratedin the drawing are illustrated for convenience of description, and thepresent disclosure is not limited to the size and the thickness of thecomponent illustrated, but it is to be noted that the relativedimensions including the relative size, location and thickness of thecomponents illustrated in various drawings submitted herewith are partof the present disclosure.

Like reference numerals refer to like elements throughout thespecification. In the following description, when the detaileddescription of the relevant known function or configuration isdetermined to unnecessarily obscure the important point of the presentdisclosure, the detailed description will be omitted. In a case where‘comprise,’ ‘have,’ and ‘include’ described in the present specificationare used, another part may be added unless ‘only∼’ is used. The terms ofa singular form may include plural forms unless referred to thecontrary.

In construing an element, the element is construed as including an errorrange although there is no explicit description.

In describing a position relationship, for example, when the positionrelationship is described as ‘upon~,’ ‘above~,’ ‘below~,’ and ‘nextto~,’ one or more portions may be arranged between two other portionsunless ‘just’ or ‘direct’ is used.

It will be understood that, although the terms “first,” “second,” etc.,may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure.

In describing elements of the present disclosure, the terms “first,”“second,” etc., may be used. These terms are intended to identify thecorresponding elements from the other elements, and basis, order, ornumber of the corresponding elements are not limited by these terms. Theexpression that an element is “connected” or “coupled” to anotherelement should be understood that the element may directly be connectedor coupled to another element but may directly be connected or coupledto another element unless specially mentioned, or a third element may beinterposed between the corresponding elements.

Features of various embodiments of the present disclosure may bepartially or overall coupled to or combined with each other, and may bevariously inter-operated with each other and driven technically as thoseskilled in the art can sufficiently understand. The embodiments of thepresent disclosure may be carried out independently from each other, ormay be carried out together in co-dependent relationship.

FIG. 1 is a schematic plan view illustrating a transparent displaypanel.

Hereinafter, X axis indicates a line parallel with a scan line, Y axisindicates a line parallel with a data line, and Z axis indicates aheight direction of a transparent display device 100.

Although a description has been described based on that the transparentdisplay device 100 according to one embodiment of the present disclosureis embodied as an organic light emitting display device, the transparentdisplay device 100 may be embodied as a liquid crystal display device, aplasma display panel (PDP), a Quantum dot Light Emitting Display (QLED)or an Electrophoresis display device.

Referring to FIG. 1 , a transparent display device according to oneembodiment of the present disclosure includes a transparent displaypanel 110. The transparent display panel 110 may include a display areaDA provided with pixels to display an image, and a non-display area NDAfor not displaying an image.

The display area DA may be provided with a first signal lines SL1, asecond signal lines SL2 and the pixels. The non-display area NDA may beprovided with a pad area PA in which pads are disposed, and at least onescan driver 205.

The first signal lines SL1 may be extended in a first direction (e.g.,Y-axis direction). The first signal lines SL1 may cross the secondsignal lines SL2 in the display area DA. The second signal lines SL2 maybe extended in the display area DA in a second direction (e.g., X-axisdirection). The pixel may be provided in an area where the first signalline SL1 and the second signal line SL2 cross each other, and emitspredetermined light to display an image.

The scan driver 205 are connected to the scan lines and supplies scansignals to the scan lines. The scan driver 205 may be disposed in thenon-display area NDA on one side or both sides of the display area DA ofthe transparent display panel 110 by a gate driver in panel (GIP) methodor a tape automated bonding (TAB) method.

The transparent display panel 110 may further include a touch line and atouch sensor in addition to the first signal line SL1, the second signalline SL2 and the pixel in order to implement a touch function. Adetailed description of the touch line and the touch sensor will bedescribed later with reference to FIGS. 2 to 16 .

FIG. 2 is a schematic view illustrating an example of a pixel providedin an area A of FIG. 1 , and FIG. 3 is a view illustrating an example ofsignal lines, touch lines and a touch sensor, which are provided in anarea B of FIG. 2 .

The display area DA, as shown in FIG. 2 , includes a transmissive areaTA and a non-transmissive area NTA. The transmissive area TA is an areathrough which most of externally incident light passes, and thenon-transmissive area NTA is an area through which most of externallyincident light fails to transmit. For example, the transmissive area TAmay be an area where light transmittance is greater than α%, forexample, about 90%, and the non-transmissive area NTA may be an areawhere light transmittance is smaller than β%, for example, about 50%. Atthis time, α is greater than β. A user may view an object or backgroundarranged over a rear surface of the transparent display panel 110 due tothe transmissive area TA.

The non-transmissive area NTA may include a first non-transmissive areaNTA1, a second non-transmissive area NTA2 and a plurality of pixels P.Pixels P may be provided to at least partially overlap at least one ofthe first signal line SL1 and the second signal line SL2, therebyemitting predetermined light to display an image. A light emission areaEA may correspond to an area, from which light is emitted, in the pixelP.

Each of the pixels P, as shown in FIG. 2 , may include at least one of afirst subpixel SP1, a second subpixel SP2, a third subpixel SP3 and afourth subpixel SP4. The first subpixel SP1 may include a first lightemission area EA1 emitting light of a first color. The second subpixelSP2 may include a second light emission area EA2 emitting light of asecond color. The third subpixel SP3 may include a third light emissionarea EA3 emitting light of a third color. The fourth subpixel SP4 mayinclude a fourth light emission area EA4 emitting light of a fourthcolor.

The first to fourth light emission area EA1, EA2, EA3 and EA4 may emitlight of different colors. For example, the first light emission areaEA1 may emit light of a green color. The second light emission area EA2may emit light of a red color. The third light emission area EA3 mayemit light of a blue color. The fourth light emission area EA4 may emitlight of a white color. However, the light emission areas are notlimited to this example. Each of the pixels P may further include asubpixel emitting light of a color other than red, green, blue andwhite. Also, the arrangement order of the subpixels SP1, SP2, SP3 andSP4 may be changed in various ways.

The first non-transmissive area NTA1 may be extended in a firstdirection (Y-axis direction) in a display area DA, and may be disposedto at least partially overlap light emission areas EA1, EA2, EA3 andEA4. A plurality of first non-transmissive areas NTA1 may be provided inthe transparent display panel 110, and a transmissive area TA may beprovided between two adjacent first non-transmissive areas NTA1. In thefirst non-transmissive area NTA1, first signals lines extended in thefirst direction (Y-axis direction) and touch lines TL extended in thefirst direction (Y-axis direction) may be disposed to be spaced apartfrom each other.

For example, the first signal lines SL1 may include at least one of apixel power line VDDL, a common power line VSSL, a reference line REFLor data lines DL1, DL2, DL3 and DL4.

The pixel power line VDDL may supply a first power source to a drivingtransistor DTR of each of subpixels SP1, SP2, SP3 and SP4 provided inthe display area DA.

The common power line VSSL may supply a second power source to a cathodeelectrode of the subpixels SP1, SP2, SP3 and SP4 provided in the displayarea DA. At this time, the second power source may be a common powersource commonly supplied to the subpixels SP1, SP2, SP3 and SP4.

The common power line VSSL may supply the second power source to thecathode electrode through a cathode contact electrode CCT providedbetween the transmissive area TA and the common power line VSSL. A powerconnection line VCL may be disposed between the common power line VSSLand the cathode contact electrode CCT. One end of the power connectionline VCL may be connected to the common power line VSSL through a firstcontact hole CH1 and the other end thereof may be connected to thecathode contact electrode CCT. The cathode electrode may be connected tothe cathode contact electrode CCT. As a result, the cathode electrodemay be electrically connected to the common power line VSSL through thepower connection line VCL and the cathode contact electrode CCT.

The reference line REFL may supply an initialization voltage (orreference voltage) to the driving transistor DTR of each of thesubpixels SP1, SP2, SP3 and SP4 provided in the display area DA.

The reference line REFL may be disposed between the plurality of datalines DL1, DL2, DL3 and DL4. For example, the reference line REFL may bedisposed at the center of the plurality of data lines DL1, DL2, DL3 andDL4, that is, between the second data line DL2 and the third data lineDL3 .

The reference line REFL may be diverged and connected to the pluralityof subpixels SP1, SP2, SP3 and SP4. In detail, the reference line REFLmay be connected to circuit elements of the plurality of subpixels SP1,SP2, SP3 and SP4 to supply an initialization voltage (or referencevoltage) to each of the subpixels SP1, SP2, SP3 and SP4.

When the reference line REFL is disposed to be close to the edge of thefirst non-transmissive area NTA1, a deviation between connection lengthsfrom a diverged point to a circuit element of a plurality of subpixelsSP1, SP2, SP3 and SP4 is increased. In a transparent display panel 110according to one embodiment of the present disclosure, the referenceline REFL is disposed in a middle area of the first non-transmissivearea NTA1, whereby the deviation between the connection lengths to thecircuit element of each of the plurality of subpixels SP1, SP2, SP3 andSP4 may be reduced or minimized. Therefore, the reference line REFL mayuniformly supply signals to the circuit elements of the plurality ofsubpixels SP1, SP2, SP3 and SP4.

Each of the data lines DL1, DL2, DL3 and DL4 may supply a data voltageto the subpixels SP1, SP2, SP3 and SP4. For example, the first data lineDL1 may supply a first data voltage to a first driving transistor of thefirst subpixel SP1, the second data line DL2 may supply a second datavoltage to a second driving transistor of the second subpixel SP2, thethird data line DL3 may supply a third data voltage to a third drivingtransistor of the third subpixel SP3 and the fourth data line DL4 maysupply a fourth data voltage to a fourth driving transistor of thefourth subpixel SP4.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the touch line TL may be further disposed in thefirst non-transmissive area NTA1. At least two touch lines TL may beprovided in the first non-transmissive area NTA1. When the plurality oftouch lines TL are disposed in the transmissive area TA of thetransparent display panel 110, light transmittance may be deteriorateddue to the plurality of touch lines TL.

Also, a slit, specifically an elongated linear or rectangular shape, maybe provided between the plurality of touch lines TL. When external lightpasses through the slit, a diffraction phenomenon may occur. Accordingto the diffraction phenomenon, light corresponding to plane waves may bechanged to spherical waves as the light passes through the slit, and aninterference phenomenon may occur in the spherical waves. Therefore,constructive interference and destructive interference occur in thespherical waves, whereby the external light that has passed through theslit may have irregular light intensity. As a result, in the transparentdisplay panel 110, definition of an object or image positioned at anopposite side may be reduced. For this reason, in one embodiment, theplurality of touch lines TL are preferably disposed in the firstnon-transmissive area NTA1 rather than the transmissive area TA.

A plurality of touch lines TL may be disposed between first signal linesSL1 in the first non-transmissive area NTA1 and a transmissive area TAas shown in FIG. 3 . For example, six touch lines TL1, TL2, TL3, TL4,TL5 and TL6 may be disposed in one first non-transmissive area NTA1.Three TL1, TL2 and TL3 of the six touch lines TL1, TL2, TL3, TL4, TL5and TL6 may be disposed between a pixel power line VDDL and thetransmissive area TA, and the other three touch lines TL4, TL5 and TL6may be disposed between a common power line VSSL and the transmissivearea TA, but are not limited to this arrangement. In one embodiment, itis beneficial to have the plurality of touch lines TL so as not tooverlap circuit areas CA1, CA2, CA3 and CA4 in which circuit elementsare disposed, and various modifications may be made in the arrangementorder of the plurality of touch lines TL with the first signal linesSL1.

The transparent display panel 110 according to one embodiment of thepresent disclosure includes a pixel P between adjacent transmissiveareas TA, and the pixel P may include light emission areas EA1, EA2, EA3and EA4 in which a light emitting element is disposed to emit light.Since a size of the non-transmissive area NTA is small in thetransparent display panel 110, the circuit element may be disposed to atleast partially overlap the light emission areas EA1, EA2, EA3 and EA4.That is, the light emission areas EA1, EA2, EA3 and EA4 may includecircuit areas CA1, CA2, CA3 and CA4 in which the circuit elements aredisposed.

For example, the circuit areas may include a first circuit area CA1 inwhich a circuit element connected to the first subpixel SP1 is disposed,a second circuit area CA2 in which a circuit element connected to thesecond subpixel SP2 is disposed, a third circuit area CA3 in which acircuit element connected to the third subpixel SP3 is disposed, and afourth circuit area CA4 in which a circuit element connected to thefourth subpixel SP4 is disposed.

In a transparent display panel 110 according to one embodiment of thepresent disclosure, a plurality of touch lines TL do not overlap circuitareas CA1, CA2, CA3 and CA4, so that parasitic capacitance of the touchlines TL due to a circuit element may be reduced or minimized.

Furthermore, the transparent display panel 110 according to oneembodiment of the present disclosure may reduce a horizontal distancedifference between the touch lines TL. Since at least two transistorsand capacitors are disposed in the circuit areas CA1, CA2, CA3 and CA4,it is difficult to form the touch lines TL in a straight line in thecircuit areas CA1, CA2, CA3 and CA4, so that the touch lines TL may havedifficulty in having a certain horizontal distance. Therefore, thehorizontal distance difference between the touch lines TL is increased,whereby uniformity in parasitic capacitance may be significantlylowered.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the touch lines TL are disposed so as not to overlapthe circuit areas CA1, CA2, CA3 and CA4, whereby influence due to thecircuit element may be reduced, and at the same time the horizontaldistance difference between the touch lines TL may be reduced to improveuniformity of parasitic capacitance.

The second non-transmissive area NTA2 may be extended in the displayarea DA in a second direction (X-axis direction), and may be disposed toat least partially overlap the light emission areas EA1, EA2, EA3 andEA4. A plurality of second non-transmissive areas NTA2 may be providedin the transparent display panel 110, and the transmissive area TA maybe provided between two adjacent second non-transmissive areas NTA2. Thesecond signal line SL2 and a touch bridge line TBL may be disposed to bespaced apart from each other in the second non-transmissive area NTA2.

A second signal line SL2 may be extended in a second direction (X-axisdirection), and may include, for example, a scan line SCANL. The scanline SCANL may supply a scan signal to the subpixels SP1, SP2, SP3 andSP4 of the pixel P.

A touch bridge line TBL may connect any one of the plurality of touchlines TL with a touch sensor TS. The touch bridge line TBL may beconnected to any one of the plurality of touch lines TL through a secondcontact hole CH2. Also, the touch bridge line TBL may be connected to atleast two touch sensors TS arranged in a second direction (X-axisdirection) while being extended in the second direction (X-axisdirection).

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the plurality of touch lines TL may be disposed in afirst non-transmissive area NTA1 not a second non-transmissive areaNTA2, so that light transmittance may be prevented from beingdeteriorated due to the plurality of touch lines TL. The secondnon-transmissive area NTA2 extended in the second direction (X-axisdirection) crosses between adjacent transmissive areas TA as shown inFIG. 3 . When a width of the second non-transmissive area NTA2 crossingthe transmissive areas TA is increased, a size of the transmissive areaTA is necessarily reduced.

When the plurality of touch lines TL are disposed in the secondnon-transmissive area NTA2, the width of the second non-transmissivearea NTA2 is increased to dispose a large number of lines, and the sizeof the transmissive area TA is reduced. That is, a problem may occur inthat light transmittance of the transparent display panel 110 is reduceddue to the plurality of touch lines TL.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the plurality of touch lines TL may be disposed inthe first non-transmissive area NTA1, and only one touch bridge line TBLfor connecting the plurality of touch sensors TS may be provided in thesecond non-transmissive area NTA2. Therefore, the transparent displaypanel 110 according to one embodiment of the present disclosure mayreduce or minimize the size decrease of the transmissive area TA ordecrease in light transmittance due to the plurality of touch lines TLand the touch bridge line TBL.

The touch sensor TS may be provided in the transmissive area TA. Thetouch sensor TS may be disposed in each of the plurality of transmissiveareas TA, and may be changed in capacitance during user contact. A touchdriver (not shown) may be connected to the plurality of touch sensors TSthrough the plurality of touch lines TL to detect a change incapacitance of the plurality of touch sensors TS.

Hereinafter, a connection relation among a plurality of touch sensorsTS, a plurality of touch lines TL and a plurality of touch bridge linesTBL will be described in more detail with reference to FIGS. 4 and 5 .

FIG. 4 is a view illustrating a connection relation between a pluralityof touch blocks and a plurality of touch lines, and FIG. 5 is a viewillustrating a connection relation between a plurality of touch linesand a plurality of touch sensors in one touch block.

Referring to FIGS. 4 to 5 , the transparent display panel 110 accordingto one embodiment of the present disclosure may include a plurality oftouch blocks TB. Each of the plurality of touch blocks TB may include aplurality of pixels P and a plurality of transmissive areas TA disposedto correspond to the plurality of pixels P one-to-one as a basic unitfor determining a user touch position. For example, each of theplurality of touch blocks TB may include 12X15 pixels P and 12X15 touchsensors TS. In this case, when image resolution is 1920X1080, touchresolution may be 160X72.

At this time, the touch sensor TS may include a touch sensor electrodeTSE. The touch sensor electrode TSE may include the same material in thesame layer as the cathode electrode CE of the pixel P. In this case, thetouch sensor electrode TSE and the cathode electrode CE may be disposedto be spaced apart from each other.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, as each of the plurality of touch lines TL isconnected to one of the plurality of touch blocks TB, a change incapacitance of the touch sensors TS provided in the connected touchblock TB may be sensed. That is, the plurality of touch lines TLprovided in the transparent display panel 110 may correspond to theplurality of touch blocks TB one-to-one. Therefore, the number of touchlines TL may be the same as the number of touch blocks TB in thetransparent display panel 110. For example, when the number of touchblocks TB is 160X72, the touch line TL may also be 160X72, and may beconnected to the touch driver TIC.

As described above, in order to form the touch lines TL as much as thenumber of touch blocks TB, at least two touch lines TL should beprovided in one first non-transmissive area NTA1. For example, whenimage resolution is 1920X1080 and touch resolution is 160X72, six touchlines TL1, TL2, TL3, TL4, TL5 and TL6 may be provided in one firstnon-transmissive area NTA1, as shown in FIG. 3 , in order to form 160X72touch lines TL in the transparent display panel 110.

The plurality of touch sensors TS provided in one touch block TB may beconnected to one of the plurality of touch lines TL provided in onetouch block TB as shown in FIG. 5 . For example, twelve firstnon-transmissive areas NTA1 may be provided in one touch block TB, andsix touch lines TL1, TL2, TL3, TL4, TL5 and TL6 may be disposed in eachof the twelve first non-transmissive areas NTA1. As a result, one touchblock TB may be provided with 72 touch lines TL1, ..., TL72. In thiscase, the plurality of touch sensors TS provided in one touch block TBmay be connected to one specific touch line TL of the 72 touch linesTL1, ..., TL72. At this time, the specific touch line TL may beconnected to the plurality of touch sensors TS arranged in the seconddirection (X-axis direction) through the touch bridge lines TBL extendedin the second direction (X-axis direction). As a result, the pluralityof touch sensors TS provided in one touch block TB may be electricallyconnected through a specific touch line TL and the touch bridge linesTBL.

Each of the plurality of touch lines TL may correspond to touch blocksTB one-to-one. Therefore, the plurality of touch blocks TB are connectedto different touch lines and thus may be electrically separated fromeach other. Each touch line TL may connect a plurality of touch sensorsTS provided in a corresponding touch block TB to a touch driver TIC. Indetail, each touch line TL may transmit the changed capacitance providedfrom the touch sensors TS provided in the touch block TB to the touchdriver TIC. The touch driver TIC may sense the changed capacitance, andmay determine a touch position of a user. Also, each touch line TL mayprovide the touch sensing voltage generated from the touch driver TIC tothe touch sensors TS provided in the touch block TB.

Hereinafter, light emitting elements of a light emission area EA, thetouch sensors TS of the transmissive area TA, and the connectionrelation between the touch sensors TS and the touch bridge line TBL willbe described in more detail with reference to FIGS. 6 to 16 .

FIG. 6 is a cross-sectional view taken along line I-I′ of FIG. 3 , FIG.7 is a cross-sectional view taken along line II-II′ of FIG. 3 , FIG. 8is a cross-sectional view taken along line III-III′ of FIG. 3 , and FIG.9 is a view illustrating an example that a defective touch sensor occursin a first undercut structure due to particles.

Referring to FIGS. 3 and 6 to 9 , a first substrate 111 of thetransparent display panel 110 according to one embodiment of the presentdisclosure may include a plurality of transmissive areas TA, and anon-transmissive area NTA that includes a plurality of light emissionareas EA disposed between the transmissive areas TA adjacent to eachother. The non-transmissive area NTA may include a firstnon-transmissive area NTA1 extended in a first direction (Y-axisdirection) and a second non-transmissive area NTA2 extended in a seconddirection (X-axis direction).

The first non-transmissive area NTA1 includes circuit areas CA1, CA2,CA3 and CA4 in which at least one transistor and a capacitor aredisposed, and may be provided with a pixel power line VDDL, a commonpower line VSSL, a reference line REFL, data lines DL and touch linesTL, which are extended in the first direction (Y-axis direction) anddisposed so as not to overlap the circuit areas CA1, CA2, CA3 and CA4.The second non-transmissive area NTA2 may include a scan line SCANL anda touch bridge line TBL, which are extended in the second direction(X-axis direction).

The at least one transistor may include a driving transistor DTR,switching transistors and a sensing transistor.

The switching transistor may be switched in accordance with a scansignal supplied to a scan line SCANL to charge a data voltage, which issupplied from the data line DL. The sensing transistor may serve tosense a threshold voltage deviation of the driving transistor DTR, whichcauses deterioration of image quality, in accordance with a sensingsignal.

The driving transistor DTR is switched in accordance with the datavoltage charged in the capacitor to generate a data current from a powersource supplied from the pixel power line VDDL and supply the datacurrent to a first electrode 120 of the subpixels SP1, SP2, SP3 and SP4.The driving transistor DTR may include an active layer ACT, a gateelectrode GE, a source electrode SE, and a drain electrode DE.

As shown in FIG. 6 , a light shielding layer LS may be provided over thefirst substrate 111. The light shielding layer LS may serve to shieldexternal light incident on an active layer ACT in an area in which adriving transistor DTR is provided. The light shielding layer LS mayinclude a single layer or multi-layer made of any one of molybdenum(Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel(Ni), neodymium (Nd) and copper (Cu), or their alloy.

The transparent display panel 110 according to one embodiment of thepresent disclosure may form at least a portion of the pixel power lineVDDL, the common power line VSSL, the reference line REFL, the datalines DL and the touch lines TL in the same layer as the light shieldinglayer LS. For example, the reference line REFL and the touch lines TLmay include the same material as that of the light shielding layer LS inthe same layer as the light shielding layer LS, but are not limitedthereto.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, as shown in FIG. 8 , a touch connection line TCL mayinclude the same material as that of the light shielding layer LS in thesame layer as the light shielding layer LS. One end of the touchconnection line TCL may be connected to the touch bridge line TBL, andthe other end thereof may be connected to a touch contact electrode TCTthrough a seventh contact hole CH7. At this time, since the touchconnection line TCL is extended from the touch bridge line TBL disposedin the second non-transmissive area NTA2 to the touch contact electrodeTCT disposed in the transmissive area TA, the touch connection line TCLcrosses a first undercut structure UC1. The first undercut structure UC1may be formed through a wet etching process. In the transparent displaypanel 110 according to one embodiment of the present disclosure, thetouch connection line TCL may be formed in the same layer as the lightshielding layer LS so that the touch connection line TCL may beprevented from being lost in the wet etching process for forming thefirst undercut structure UC1.

A buffer layer BF may be provided over the light shielding layer LS. Thebuffer layer BF is to protect the transistors DTR from water permeatedthrough the first substrate 111 vulnerable to water permeation, and mayinclude an inorganic layer, for example, a silicon oxide layer (SiOx), asilicon nitride layer (SiNx) or a multi-layer of the silicon oxide layerand the silicon nitride layer.

An active layer ACT of the driving transistor DTR may be provided overthe buffer layer BF. The active layer ACT may include a silicon-basedsemiconductor material or an oxide-based semiconductor material.

A gate insulating layer GI may be provided over the active layer ACT ofthe driving transistor DTR. The gate insulating layer GI may be providedin the non-transmissive area NTA and the transmissive area TA. However,in order to form the first undercut structure UC1 in the transmissivearea TA, the gate insulating layer GI may be provided with a firstopening area OA1 that is formed to expose the buffer layer BF withoutbeing provided in at least a portion of the transmissive area TA. Thegate insulating layer GI may include an inorganic layer, for example, asilicon oxide layer (SiOx), a silicon nitride layer (SiNx) or amulti-layer of the silicon oxide layer and the silicon nitride layer.

A gate electrode GE of the driving transistor DTR may be provided overthe gate insulating layer GI. The gate electrode GE may include a singlelayer or multi-layer made of one of molybdenum (Mo), aluminum (Al),chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) andcopper (Cu), or their alloy.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, as shown in FIG. 7 , a power connection line VCL mayinclude the same material as that of the gate electrode GE. One end ofthe power connection line VCL may be connected to the common power lineVSSL through a first contact hole CH1, and the other end thereof may beconnected to a cathode contact electrode CCT through a sixth contacthole CH6.

Also, as shown in FIG. 8 , in the transparent display panel 110according to one embodiment of the present disclosure, a first touchbridge line TBL1 may include the same material as that of the gateelectrode GE in the same layer as the gate electrode GE. In detail, thetouch bridge line TBL may include a first touch bridge line TBL1including the same material as that of the gate electrode GE in the samelayer as the gate electrode GE and a second touch bridge line TBL2including the same material as that of the light shielding layer LS inthe same layer as the light shielding layer LS. The first touch bridgeline TBL1 may be disposed in an area of the second non-transmissive areaNTA2, which overlaps the first non-transmissive area NTA1, and thus maybe connected to one of the plurality of touch lines TL through a secondcontact hole CH2. The second touch bridge line TBL2 may be disposed inan area of the second non-transmissive area NTA2, which does not overlapthe first non-transmissive area NTA1, and thus may be connected to thefirst touch bridge line TBL 1 through a fourth contact hole CH4.

The touch bridge line TBL is shown as including two layers in FIG. 8 ,but is not limited thereto. In another embodiment, the touch bridge lineTBL may include only the first touch bridge line TBL1 including the samematerial as that of the gate electrode GE in the same layer as the gateelectrode GE. The first touch bridge line TBL1 may be connected to oneof the plurality of touch lines TL through the second contact hole CH2in an area of the second non-transmissive area NTA2, which overlaps thefirst non-transmissive area NTA1. Also, the first touch bridge line TBL1may be extended in the second direction (X-axis direction) to beconnected to the touch connection line TCL through a contact hole.

An interlayer dielectric layer ILD may be provided over the gateelectrode GE of the driving transistor DTR. The interlayer dielectriclayer ILD may be provided in the non-transmissive area NTA and thetransmissive area TA. However, the interlayer dielectric layer ILD maybe provided with a first opening area OA1, which exposes the bufferlayer BF without being provided in at least a portion of thetransmissive area TA, to form a first undercut structure UC1 in thetransmissive area TA. The interlayer dielectric layer ILD may include aninorganic layer, for example, a silicon oxide layer (SiOx), a siliconnitride layer (SiNx) or a multi-layer of the silicon oxide layer and thesilicon nitride layer.

A source electrode SE and a drain electrode DE of the driving transistorDTR may be provided over the interlayer dielectric layer ILD. The sourceelectrode SE and the drain electrode DE of the driving transistor DTRmay be connected to the active layer ACT of the driving transistor DTRthrough a fifth contact hole CH5 passing through the gate insulatinglayer GI and the interlayer dielectric layer ILD. The source electrodeSE and the drain electrode DE of the driving transistor DTR may includea single layer or multi-layer made of one of molybdenum (Mo), aluminum(Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium(Nd) and copper (Cu), or their alloy.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, at least a portion of the pixel power line VDDL, thecommon power line VSSL, the reference line REFL, the data lines DL andthe touch lines TL may be formed in the same layer as the sourceelectrode SE and the drain electrode DE of the driving transistor DTR.For example, the pixel power line VDDL, the common power line VSSL andthe data lines DL may include the same material as that of the sourceelectrode SE and the drain electrode DE in the same layer as the sourceelectrode SE and the drain electrode DE, but are not limited thereto.

Also, as shown in FIG. 7 , in the transparent display panel 110according to one embodiment of the present disclosure, the cathodecontact electrode CCT may include the same material as that of thesource electrode SE and the drain electrode DE in the same layer as thesource electrode SE and the drain electrode DE. First and secondpassivation layers PAS1 and PAS2 may be provided with a second openingarea OA2 that is formed to expose at least a portion of an upper surfaceof the cathode contact electrode CCT. A second undercut structure UC2may be formed in such a manner that a planarization layer PLN is moreprotruded than the first and second passivation layers PAS1 and PAS2 inthe second opening area OA2 of the first and second passivation layersPAS1 and PAS2. Therefore, the second undercut structure UC2 may exposeat least a portion of a lower surface of the planarization layer PLN,and may expose at least a portion of the upper surface of the cathodecontact electrode CCT without having the first and second passivationlayers PAS1 and PAS2 below the exposed lower surface. The cathodecontact electrode CCT may be connected to a cathode electrode CE overthe upper surface exposed by the second undercut structure UC2. Thecathode contact electrode CCT may be connected to the power connectionline VCL through the sixth contact hole CH6, and may transfer a cathodepower source supplied from the common power line VSSL to the cathodeelectrode CE through the power connection line VCL.

Also, as shown in FIG. 8 , in the transparent display panel 110according to one embodiment of the present disclosure, a connectionelectrode CTE may include the same material as that of the sourceelectrode SE and the drain electrode DE in the same layer as the sourceelectrode SE and the drain electrode DE. The connection electrode CTEmay electrically connect the touch connection line TCL with the touchcontact electrode TCT. One end of the connection electrode CTE may beconnected to the touch connection line TCL through the seventh contacthole CH7, and the other end thereof may be connected to the touchcontact electrode TCT through an eighth contact hole CH8. In FIG. 8 ,the touch connection line TCL is shown as being connected to the touchcontact electrode TCT through the connection electrode CTE, but is notlimited thereto. In another embodiment, the touch connection line TCLmay be directly connected to the touch contact electrode TCT, and inthis case, the touch contact electrode TCT may be formed in the samelayer as the source electrode SE and the drain electrode DE.

The first passivation layer PAS1 for insulating the driving transistorDTR may be provided over the source electrode SE and the drain electrodeDE of the driving transistor DTR, and the second passivation layer PAS2may be provided over the first passivation layer PAS1.

The first and second passivation layers PAS1 and PAS2 may be provided inthe non-transmissive area NTA and the transmissive area TA. However, thefirst and second passivation layers PAS1 and PAS2 may be provided with afirst opening area OA1, which exposes the buffer layer BF without beingprovided in at least a portion of the transmissive area TA, to form thefirst undercut structure UC1 in the transmissive area TA. The firstopening area OA1 of the first and second passivation layers PAS1 andPAS2 may at least partially overlap the first opening area OA1 of theinterlayer dielectric layer ILD and the first opening area OA1 of thegate insulating layer GI. The first and second passivation layers PAS1and PAS2 may include an inorganic layer, for example, a silicon oxidelayer (SiOx), a silicon nitride layer (SiNx) or a multi-layer of thesilicon oxide layer and the silicon nitride layer.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, as shown in FIG. 8 , the touch contact electrode TCTmay be disposed between the first passivation layer PAS1 and the secondpassivation layer PAS2 to electrically connect the touch connection lineTCL with the touch sensor electrode TSE. The touch contact electrode TCTmay be connected to the connection electrode CTE through the eighthcontact hole CH8, and may be electrically connected to the touchconnection line TCL through the connection electrode CTE.

Also, at least a portion of the upper surface of the touch contactelectrode TCT may be exposed by a third undercut structure UC3, and thetouch sensor electrode TSE may be connected to the exposed uppersurface. In detail, the second passivation layer PAS2 may be providedwith a third opening area OA3 that is formed to expose at least aportion of the upper surface of the touch contact electrode TCT. Thethird undercut structure UC3 may be formed in such a manner that theplanarization layer PLN is more protruded than the second passivationlayer PAS2 in the third opening area OA3 of the second passivation layerPAS2. Therefore, the third undercut structure UC3 may expose at least aportion of the lower surface of the planarization layer PLN, and mayexpose at least a portion of the upper surface of the touch contactelectrode TCT without having the second passivation layer PAS2 below theexposed lower surface. The third undercut structure UC3 may be providedinside the area where the first undercut structure UC1 is provided. Thatis, the third undercut structure UC3 may be disposed in an area in whichthe touch sensor TS is provided.

The touch sensor electrode TSE may be deposited on the exposed uppersurface of the touch contact electrode TCT, and may be electricallyconnected with the touch contact electrode TCT. The touch contactelectrode TCT may transfer a change in capacitance of the touch sensorelectrode TSE to the touch line TL through the touch connection line TCLand the touch bridge line TBL.

The planarization layer PLN may be provided over the second passivationlayer PAS2 to planarize a step difference due to the driving transistorDTR and the plurality of signal lines. The planarization layer PLN maybe provided in the non-transmissive area NTA, and may not be provided inat least a portion of the transmissive area TA to form the firstundercut structure UC1 in the transmissive area TA. The planarizationlayer PLN may include an organic layer such as an acrylic resin, anepoxy resin, a phenolic resin, a polyamide resin and a polyimide resin.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the first undercut structure UC1 may be formed usingthe planarization layer PLN and the plurality of inorganic insulatinglayers, for example, the first and second passivation layers PAS1 andPAS2, the interlayer dielectric layer ILD and the gate insulating layerGI. In detail, the first undercut structure UC1 may be formed in such amanner that the planarization layer PLN is more protruded than theplurality of inorganic insulating layers, for example, the first andsecond passivation layers PAS1 and PAS2, the interlayer dielectric layerILD and the gate insulating layer GI in a direction of the transmissivearea TA. Therefore, the first undercut structure UC1 may expose at leasta portion of the lower surface of the planarization layer PLN, and theplurality of inorganic insulating layers may not be provided below theexposed lower surface so that a gap space with the buffer layer BF maybe provided.

The first undercut structure UC1 may be formed through a wet etchingprocess. The wet etching process for forming the first undercutstructure UC1 may be isotropic etching in view of properties. Therefore,in the first undercut structure UC1, a first gap distance d1 from an endof the planarization layer PLN to an end of the plurality of inorganicinsulating layers may be formed in the same manner as a second gapdistance d2 from the lower surface of the planarization layer PLN to theupper surface of the buffer layer BF. At this time, the first gapdistance d1 of the first undercut structure UC1 should have a minimumdistance value, for example, 2um or more in order to make sure ofisolation between the cathode electrode CE and the touch sensorelectrode TSE. Therefore, since the second gap distance d2 of the firstundercut structure UC1 should be greater than or equal to 2um, a sum ofthicknesses of the first and second passivation layers PAS1, PAS2, theinterlayer dielectric layer ILD and the gate insulating film GI may be2um or more.

The first undercut structure UC1 is provided in the transmissive areaTA, and may have a planar closed shape. For example, the first undercutstructure UC1 may be provided along an edge of the transmissive area TA.At this time, the first undercut structure UC1 may be provided tosurround the touch sensor TS.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the first undercut structure UC1 may be formed usingthe planarization layer PLN and the plurality of inorganic insulatinglayers, whereby light transmittance may be prevented from being reduceddue to the first undercut structure UC1.

A light emitting element, which includes a first electrode 120, anorganic light emitting layer 130 and a second electrode 140, and a bank125 may be provided over the planarization layer PLN.

The first electrode 120 may be provided over the planarization layer PLNfor each of the subpixels SP1, SP2, SP3 and SP4. The first electrode 120is not provided in the transmissive area TA. The first electrode 120 maybe connected to the driving transistor DTR. In detail, the firstelectrode 120 may be connected to one of the source electrode SE and thedrain electrode DE of the driving transistor DTR through a contact hole(not shown) that passes through the planarization layer PLN and thefirst and second passivation layer PAS1 and PAS2.

The first electrode 120 may include a metal material having highreflectance, such as a stacked structure (Ti/Al/Ti) of aluminum andtitanium, a stacked structure (ITO/A1/ITO) of aluminum and ITO, an Agalloy, a stacked structure (ITO/Ag alloy/ITO) of Ag alloy and ITO, aMoTi alloy, and a stacked structure (ITO/MoTi alloy/ITO) of MoTi alloyand ITO. The Ag alloy may be an alloy of silver (Ag), palladium (Pd),copper (Cu), etc. The MoTi alloy may be an alloy of molybdenum (Mo) andtitanium (Ti). The first electrode 120 may be an anode electrode.

The bank 125 may be provided over the planarization layer PLN. The bank125 may be provided to at least partially cover an edge of the firstelectrode 120 and expose a portion of the first electrode 120.Therefore, the bank 125 may prevent a problem in which light emittingefficiency is deteriorated due to concentration of a current on an endof the first electrode 120.

The bank 125 may define light emission areas EA1, EA2, EA3 and EA4 ofthe subpixels SP1, SP2, SP3 and SP4. The light emission areas EA1, EA2,EA3 and EA4 of each of the subpixels SP1, SP2, SP3 and SP4 represent anarea in which the first electrode 120, the organic light emitting layer130 and the cathode electrode CE are sequentially stacked and holes fromthe first electrode 120 and electrons from the cathode electrode CE arecombined with each other in the organic light emitting layer 130 to emitlight. In this case, the area in which the bank 125 is provided maybecome the non-light emission area NEA because light is not emittedtherefrom, and the area in which the bank 125 is not provided and thefirst electrode is exposed may become the light emission area EA.

The bank 125 may include an organic layer such as an acrylic resin, anepoxy resin, a phenolic resin, a polyamide resin, and a polyimide resin.

The organic light emitting layer 130 may be disposed over the firstelectrode 120. The organic light emitting layer 130 may include a holetransporting layer, a light emitting layer and an electron transportinglayer. In this case, when a voltage is applied to the first electrode120 and the cathode electrode CE, holes and electrons move to the lightemitting layer through the hole transporting layer and the electrontransporting layer, respectively and are combined with each other in thelight emitting layer to emit light.

In one embodiment, the organic light emitting layer 130 may be a commonlayer commonly provided in the subpixels SP1, SP2, SP3 and SP4. In thiscase, the light emitting layer may be a white light emitting layer foremitting white light.

In another embodiment, the light emitting layer of the organic lightemitting layer 130 may be provided for each of the subpixels SP1, SP2,SP3 and SP4. For example, a green light emitting layer for emittinggreen light may be provided in the first subpixel SP1, a red lightemitting layer for emitting red light may be provided in the secondsubpixel SP2, a blue light emitting layer for emitting blue light may beprovided in the third subpixel SP3, and a white light emitting layer foremitting white light may be provided in the fourth subpixel SP4. In thiscase, the light emitting layer of the organic light emitting layer 130is not provided in the transmissive area TA.

An organic light emitting layer 130 may be separated between thenon-transmissive area NTA and the transmissive area TA by the firstundercut structure UC1. In detail, the organic light emitting layer 130may be separated into an organic light emitting layer 131 provided inthe non-transmissive area NTA and an organic light emitting layer 132provided in the transmissive area TA by the first undercut structureUC1. That is, the organic light emitting layer 131 provided in thenon-transmissive area NTA and the organic light emitting layer 132provided in the transmissive area TA may be spaced apart from each otherby the first undercut structure UC1.

A second electrode 140 may be disposed over the organic light emittinglayer 130 and the bank 125. When the second electrode 140 is depositedon an entire surface, the second electrode 140 may be separated withoutbeing continuous between the non-transmissive area NTA and thetransmissive area TA by the first undercut structure UC1. In detail, thesecond electrode 140 may be separated into a second electrode CEprovided in the non-transmissive area NTA and a second electrode TSEprovided in the transmissive area TA by the first undercut structureUC1.

In this case, the second electrode CE provided in the non-transmissivearea NTA may be a cathode electrode CE, and is an element constituting alight emitting element. The cathode electrode CE may be connected to acathode contact portion CCT to receive a power source from the commonpower line VSSL. The cathode electrode CE may be a common layer that iscommonly provided in the subpixels SP1, SP2, SP3 and SP4 to apply thesame voltage.

Also, the second electrode TSE provided in the transmissive area TA is atouch sensor electrode TSE, and may be an element constituting the touchsensor TS. The touch sensor electrode TSE may be connected to a touchcontact electrode TCT to provide a change in capacitance to the touchline TL.

The second electrode 140, which includes the cathode electrode CE andthe touch sensor electrode TSE, may include a transparent conductivematerial (TCO) such as ITO and IZO, which may transmit light, or asemi-transmissive conductive material such as magnesium (Mg), silver(Ag) or an alloy of magnesium (Mg) and silver (Ag). When the secondelectrode 140 includes a semi-transmissive conductive material, lightemitting efficiency may be increased by a micro cavity.

An encapsulation layer 150 may be provided over the light emittingelements and the touch sensors TS. The encapsulation layer 150 may beprovided over the cathode electrode CE and the touch sensor electrodeTSE to at least partially cover the cathode electrode CE and the touchsensor electrode TSE.

The encapsulation layer 150 serves to prevent oxygen or water from beingpermeated into the organic light emitting layer 130, the cathodeelectrode CE and the touch sensor electrode TSE. Accordingly, in someembodiments, the encapsulation layer 150 may include at least oneinorganic layer and at least one organic layer.

A color filter CF may be provided over the encapsulation layer 150. Thecolor filter CF may be provided over one surface of the second substrate112 that faces the first substrate 111. In this case, the firstsubstrate 111 provided with the encapsulation layer 150 and the secondsubstrate 112 provided with the color filter CF may be bonded to eachother by an adhesive layer 160. At this time, the adhesive layer 160 maybe an optically clear resin (OCR) layer or an optically clear adhesive(OCA) film.

The color filter CF may be provided to be patterned for each of thesubpixels SP1, SP2, SP3 and SP4. A black matrix BM may be providedbetween color filters CF. The black matrix BM may be disposed betweenthe subpixels SP1, SP2, SP3 and SP4 to prevent a color mixture fromoccurring between adjacent subpixels SP1, SP2, SP3 and SP4. In addition,the black matrix BM may prevent light incident from the outside frombeing reflected by the plurality of lines, for example, the scan linesSCANL, the pixel power line VDDL, the common power line VSSL, thereference line REFL, data lines DL, etc., provided between the subpixelsSP1, SP2, SP3 and SP4.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the touch sensor electrode TSE of the touch sensorTS and the cathode electrode CE of the light emitting element may beprovided in the same layer using the first undercut structure UC1. Inthe transparent display panel 110 according to one embodiment of thepresent disclosure, a touch process is simplified, and a separate maskfor the touch sensor electrode TSE is not required.

Also, in the transparent display panel 110 according to one embodimentof the present disclosure, the first undercut structure UC1 may beformed using the planarization layer PLN and the plurality of inorganicinsulating layers, whereby the first undercut structure UC1 may beformed without loss of light transmittance.

Also, in the transparent display panel 110 according to one embodimentof the present disclosure, the touch lines TL may be disposed below thelight emitting element, whereby light emitting efficiency of the pixel Pmay be prevented from being deteriorated due to the touch lines TL.

Also, in the transparent display panel 110 according to one embodimentof the present disclosure, the touch lines TL may be disposed so as notto overlap the circuit areas CA1, CA2, CA3 and CA4, whereby influencecaused by the circuit element may be reduced or minimized and at thesame time uniformity of parasitic capacitance may be improved.

Also, in the transparent display panel 110 according to one embodimentof the present disclosure, the plurality of touch lines TL may bedisposed in the first non-transmissive area NTA1, and only one touchbridge line TBL for connecting the plurality of touch sensors TS may beprovided in the second non-transmissive area NTA2, whereby decrease in asize of the transmissive area TA or decrease in light transmittance dueto the plurality of touch lines TL and the touch bridge line TBL may bereduced or minimized.

As described above, in the transparent display panel 110 according toone embodiment of the present disclosure, the touch sensor electrode TSEof the touch sensor TS and the cathode electrode CE of the lightemitting element may be separated from each other by the first undercutstructure UC1. However, in the manufacturing process, particles PRT mayoccur in the first undercut structure UC1 as shown in FIG. 9 . In thiscase, the touch sensor electrode TSE of the touch sensor TS and thecathode electrode CE of the light emitting element may be electricallyconnected to each other without being separated from each other.

Since all of the touch sensors TS included in one touch block TB areelectrically connected to one another, all the touch sensors TS includedin the corresponding touch block TB are not normally operated eventhough a defect occurs only in one of the touch sensors TS. Therefore,as shown in FIG. 9 , when the touch sensor electrode TSE of the touchsensor TS and the cathode electrode CE of the light emitting element areconnected to each other to generate the defective touch sensor TS, atouch of a user is not sensed in the entire touch block TB in which thedefective touch sensor TS is included. In this case, a plurality ofdefective touch sensors TS may be generated, and may be disposed ontheir respective touch blocks TB different from one another. In thiscase, all of the plurality of touch blocks TB in which the plurality ofdefective touch sensors TS are disposed may not sense the touch, andconsequently, a touch defect rate of the transparent display panel 110may be increased.

The transparent display panel 110 according to one embodiment of thepresent disclosure may include elements capable of specifying a linearea in which the defective touch sensor TS of the plurality of touchsensors TS included in one touch block TB is included. In addition, inthe transparent display panel 110 according to one embodiment of thepresent disclosure, the touch sensors TS included in the specified linearea and the touch bridge line TBL may be electrically separated fromeach other through a repair process.

Hereinafter, the elements capable of specifying the line area in whichthe defective touch sensor TS is included will be described withreference to FIGS. 10 to 16 , and a case that the line area in which thedefective touch sensor TS is included is detected using the elementswill be described.

FIG. 10 is a view illustrating an example that a high resistance area isformed in a second cathode power area, FIG. 11 is a view illustratinganother example that a high resistance area is formed in a secondcathode power area, FIG. 12 is a cross-sectional view taken along lineIV-IV′ of FIG. 11 , FIGS. 13A to 13C are views illustrating a currentpath when a defective touch sensor occurs, FIG. 14 is a viewillustrating luminance of a plurality of pixels when a defective touchsensor occurs, FIG. 15 is a view illustrating an example that adefective touch sensor occurs in one touch block, and FIG. 16 is a graphillustrating a current per line of a plurality of pixels provided in thetouch block of FIG. 15 .

As shown in FIGS. 10 to 12 , in the transparent display panel 110according to one embodiment of the present disclosure, a high resistancearea may be provided in a cathode power area CPA to which a cathodepower source is applied, and a line area in which the defective touchsensor TS is included may be detected using the high resistance area.

In detail, the non-transmissive area NTA may include a cathode powerarea CPA to which a cathode power source is applied. The cathode powerarea CPA may include a first cathode power area CPA1 provided betweentwo touch sensors TS adjacent to each other in the second direction(X-axis direction) and a second cathode power area CPA2 provided betweentwo touch sensors TS adjacent to each other in the first direction(Y-axis direction).

The transparent display panel 110 according to one embodiment of thepresent disclosure is characterized in that the second cathode powerarea CPA2 has resistance higher than that of the first cathode powerarea CPA1. In one embodiment, the second cathode power area CPA2 may bea high resistance area having resistance of 1kΩ or more.

As one of methods of implementing the second cathode power area CPA2 asthe high resistance area, the cathode electrode CE may be formed to bethin as shown in FIG. 10 .

The cathode electrode CE may include a first cathode electrode CE1 and asecond cathode electrode CE2. The first cathode electrode CE1 may bedisposed to at least partially overlap the common power line VSSLextended in the first direction (Y-axis direction). The first cathodeelectrode CE1 may be connected to the common power line VSSL through thepower connection line VCL and the cathode contact electrode CCT so thata cathode power source from the common power line VSSL may be appliedthereto. The first cathode electrode CE1 may be provided in the firstcathode power area CPA1, and may have a first width W1.

The second cathode electrode CE2 may be provided in the second cathodepower area CPA2, and may have a second width W2. The second cathodeelectrode CE2 is in contact with the first cathode electrode CE1, andthe cathode power source from the common power line VSSL may be appliedthereto through the first cathode electrode CE1.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the second width W2 of the second cathode electrodeCE2 may be thinner than the first width W1, so that the second cathodeelectrode CE2 may have resistance of 1kΩ or more. In one embodiment, thesecond width W2 of the second cathode electrode CE2 may be smaller than50 µm. Therefore, high resistance of 1 kΩ or more may be implemented inthe second cathode power area CPA2 in which the second cathode electrodeCE2 is provided.

As the other one of the methods of implementing the second cathode powerarea CPA2 as the high resistance area, the common power line VSSL mayinclude a high resistance material as shown in FIGS. 11 and 12 .

The common power line VSSL may include a first common power line VSSL1and a second common power line VSSL2. The first common power line VSSL1may be provided in the first cathode power area CPA1 and extended in thefirst direction (Y-axis direction). The first common power line VSSL1may include a plurality of layers. The first common power line VSSL1 mayinclude a first line provided in a first layer and a second lineprovided in a second layer, wherein the first line and the second linemay be electrically connected to each other through a contact hole. Forexample, the first common power line VSSL1 may include a first lineprovided in the same layer as the source electrode SE and the drainelectrode DE of the driving transistor DTR and a second line provided ina layer provided between the first passivation layer PAS1 and the secondpassivation layer PAS2. The first common power line VSSL1 may have athird width W3. The first common power line VSSL1 may be connected tothe cathode electrode CE through the power connection line VCL and thecathode contact electrode CCT to apply the cathode power source to thecathode electrode CE.

The second common power line VSSL2 may be extended in the seconddirection (X-axis direction). The second common power line VSSL2 may beconnected to the first common power line VSSL1 through a ninth contacthole CH9, so that the cathode power source may be applied theretothrough the first common power line VSSL1.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the second common power line VSSL2 may include ahigh resistance material, so that the second common power line VSSL2 mayhave resistance of 1 kΩ or more. In one embodiment, the second commonpower line VSSL2 may include a silicon-based semiconductor material oran oxide-based semiconductor material. For example, the second commonpower line VSSL2 may include the same material as that of the activelayer ACT of the driving transistor DTR in the same layer as the activelayer ACT of the driving transistor DTR as shown in FIG. 12 . The secondcommon power line VSSL2 provided in the same layer as the active layerACT may be connected to the first common power line VSSL1 provided inthe same layer as the source electrode SE and the drain electrode DEthrough the ninth contact hole CH9.

The second common power line VSSL2 may have a fourth width W4 smallerthan the third width W3. Since the second common power line VSSL2 thinlyincludes a silicon-based semiconductor material or an oxide-basedsemiconductor material as compared with the first common power lineVSSL1 and includes a single layer, the second common power line VSSL2may have high resistance. High resistance of 1 kΩ or more may beimplemented in the second cathode power area CPA2 provided in the secondcommon power line VSSL2.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the high resistance area having high resistance of 1kΩ or more may be provided in the cathode power area CPA as describedabove, whereby the line area in which the defective touch sensor TS isincluded may be detected.

Referring to FIGS. 13A to 13C, in the transparent display panel 110according to one embodiment of the present disclosure, the common powerline VSSL may be floated to detect the defective touch sensor TS. Thetransparent display panel 110 according to one embodiment of the presentdisclosure may further include a switching transistor STR to float thecommon power line VSSL. The switching transistor STR may connect ordisconnect the common power line VSSL to or from a cathode power supplysource in accordance with a control signal. The switching transistor STRmay separate the common power line VSSL from the cathode power supplysource in accordance with a defect detection control signal of aturn-off level. When the switching transistor STR is turned off, thecommon power line VSSL may be in a floating state. In addition, theswitching transistor STR may connect the common power line VSSL to thecathode power supply source in accordance with a general control signalof a turn-on level. When the switching transistor STR is turned on, acathode power source EVSS from the cathode power supply source may beapplied to the common power line VSSL. The common power line VSSL maytransfer the cathode power source EVSS to the cathode electrode CE.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, a voltage may be applied to each of the pixel powerline VDDL and the touch line TL. In the transparent display panel 110according to one embodiment of the present disclosure, a first voltage,e.g., 24 V may be applied to the pixel power line VDDL, and a secondvoltage lower than the first voltage, e.g., 0 V may be applied to thetouch line TL. At this time, the pixel power line VDDL may be connectedto each of subpixels R, W, B and G of pixels P1, P2, P3 and P4. Thetouch line TL may be connected to each of a plurality of touch sensorsTS1, TS2, TS3 and TS4 through the touch bridge line TBL.

When a short-circuit occurs between the touch sensor electrode TSE ofthe third touch sensor TS3 and the cathode electrode CE of the thirdpixel P3, the touch sensor electrode TSE of the third touch sensor TS3may be electrically connected to the cathode electrode CE of the thirdpixel P3. In this case, a first current may be generated from the pixelpower line VDDL of the first voltage to the touch line TL of the secondvoltage as shown in FIG. 13A. In detail, a first current flows from thepixel power line VDDL to the touch sensor electrode TSE of the thirddefective touch sensor TS3 by passing through the cathode electrode CEof the third defective pixel P3, and flows from the touch sensorelectrode TSE of the third defective touch sensor TS3 to the touch lineTL by passing through the touch bridge line TBL, whereby a first currentpath CP1 may be formed.

Meanwhile, the current may be generated between peripheral pixels P1 andP2 and the third defective touch sensor TS3 having a defect in additionto the third defective pixel P3 having a defect.

As shown in FIG. 13B, a second current may be generated between thefirst normal pixel P1 and the third defective touch sensor TS3 having adefect. In this case, the first normal pixel P1 may be a normal pixelconnected to the same pixel power line VDDL as that of the thirddefective pixel P3 having a defect, and may include pixels disposed inthe first direction (Y-axis direction) from the third defective pixelP3.

In detail, the second current flows from the pixel power line VDDL tothe touch sensor electrode TSE of the third defective touch sensor TS3by passing through the cathode electrode CE of the first normal pixel P1and the cathode electrode CE of the third defective pixel P3 and flowsfrom the touch sensor electrode TSE of the third defective touch sensorTS3 to the touch line TL by passing through the touch bridge line TBL,whereby a second current path CP2 may be formed.

At this time, the second current may flow from the cathode electrode CEof the first normal pixel P1 to the cathode electrode CE of the thirddefective pixel P3 through the first cathode electrode CE1 provided inthe first cathode power area CPA1 extended in the first direction(Y-axis direction) or the first common power line VSSL1. The firstcommon power line VSSL1 may include a plurality of layers, and may havea third width W3 that is wider than that of the second common power lineVSSL2. In addition, the first cathode electrode CE1 may have a firstwidth W1 that is wider than that of the second cathode electrode CE2. Asa result, the first cathode power area CPA1 may have low resistance.Therefore, even though the second current passes through the firstcathode electrode CE1 provided in the first cathode power area CPA1 orthe first common power line VSSL1 between the cathode electrode CE ofthe first normal pixel P1 and the cathode electrode CE of the thirddefective pixel P3, its amount may not be significantly reduced. Thatis, the second current may be equal to or similar to the first current.

As shown in FIG. 13C, a third current may be generated between thesecond normal pixel P2 and the third defective touch sensor TS3 having adefect. In this case, the second normal pixel P2 may be a normal pixelconnected to the pixel power line VDDL different from the pixel powerline VDDL to which the third defective pixel P3 having a defect isconnected, and may include pixels disposed in the second direction(X-axis direction) from the third defective pixel P3..

In detail, the third current flows from the pixel power line VDDL to thetouch sensor electrode TSE of the third defective touch sensor TS3 bypassing through the cathode electrode CE of the second normal pixel P2and the cathode electrode CE of the third defective pixel P3 and flowsfrom the touch sensor electrode TSE of the third defective touch sensorTS3 to the touch line TL by passing through the touch bridge line TBL,whereby a third current path CP3 may be formed.

At this time, the third current may flow from the cathode electrode CEof the second normal pixel P2 to the cathode electrode CE of the thirddefective pixel P3 through the second cathode electrode CE2 provided inthe second cathode power area CPA2 extended in the second direction(X-axis direction) or the second common power line VSSL2. The secondcommon power line VSSL2 may include a single layer, may be made of asilicon-based semiconductor material or an oxide-based semiconductormaterial, and may have a fourth width W4 that is thinner than that ofthe first common power line VSSL1. In addition, the second cathodeelectrode CE2 may have a second width W2 that is thinner than that ofthe first cathode electrode CE1. As a result, the second cathode powerarea CPA2 may have high resistance Revss. Therefore, when the thirdcurrent passes through the second cathode electrode CE2 provided in thesecond cathode power area CPA2 or the second common power line VSSL2between the cathode electrode CE of the second normal pixel P2 and thecathode electrode CE of the third defective pixel P3, its amount may besignificantly reduced by high resistance Revss. That is, the amount ofthe third current may be smaller than the first current or the secondcurrent.

Consequently, the current flows to the second normal pixel P2 disposedin the second direction (X-axis direction) in the third defective pixelP3 at a smaller amount than that of the third defective pixel P3.Therefore, as shown in FIG. 14 , luminance of the second normal pixel P2may be smaller than that of the third defective pixel P3. Further, asthe second normal pixel P2 becomes far away from the third defectivepixel P3 in the second direction (X-axis direction), a length of thesecond normal pixel P2, which passes through the second cathodeelectrode CE2 provided in the second cathode power area CPA2 or thesecond common power line VSSL2, is increased, whereby the amount of thecurrent that is reduced may be increased. Therefore, as shown in FIG. 14, as the second normal pixel P2 becomes far away from the thirddefective pixel P3 in the second direction (X-axis direction), itsluminance may be reduced.

Meanwhile, since all of the first current, the second current and thethird current pass through the third defective pixel P3, the thirddefective pixel P3 may have luminance higher than that of the pixels P1,P2 and P4 adjacent thereto. Therefore, when the first voltage and thesecond voltage are applied to the pixel power line VDDL and the touchline TL, respectively, a bright line B in the first direction (Y-axisdirection) occurs in points SCP1 and SCP2, in which a short-circuitoccurs, between the touch sensor electrode TSE of the touch sensor TSand the cathode electrode CE of the pixel P as shown in FIG. 14 .

In the transparent display panel 110 according to one embodiment of thepresent disclosure, a line area in which the defective touch sensor TSis included may be detected in one touch block TB by using the fact thatthe bright line B of the first direction (Y-axis direction) occurs inthe points SCP1 and SCP2 in which a short-circuit occurs. In detail, thetransparent display panel 110 according to one embodiment of the presentdisclosure may include a defect detector 210 for detecting the defectivetouch sensor TS. The defect detector 210 may be an element included inan external circuit board (not shown), or may be an element included inan external defect inspection equipment.

The defect detector 210 may detect a touch block TB, in which thedefective touch sensor TS is included, by sensing the plurality of touchlines TL connected to the plurality of touch blocks TB one-to-one. Asshown in FIG. 15 , one touch block TB may include a plurality of touchline areas TLA in which the plurality of touch sensors TS are disposedin a line in the first direction (Y-axis direction) and a plurality ofpixel line areas PLA in which the plurality of pixels P are disposed ina line in the first direction (Y-axis direction). The plurality of pixelline areas PLA may be disposed to correspond to the plurality of touchline areas TLA one-to-one, and the pixel power line VDDL may be providedin each of the plurality of pixel line areas PLA.

The defect detector 210 may detect the touch line area TLA, in which thedefective touch sensor TS is included, in the touch block TB. To thisend, the defect detector 210 may control the switching transistor STR tobe turned off, thereby separating the common power line VSSL from thecathode power supply source. The defect detector 210 may control thefirst voltage, for example, 24 V, to be applied to the pixel power lineVDDL, and may control the second voltage lower than the first voltage,e.g., 0 V, to be applied to the touch line TL.

The defect detector 210 may sense the current per pixel line areas PLAof the plurality of pixels P through the pixel power line VDDL providedin each of the plurality of pixel line areas PLA. The defect detector210 may detect the defective touch line area TLA, in which the defectivetouch sensor TS is included, based on the current per pixel line areaPLA of the plurality of pixels P. The defect detector 210 may check thepixel line area PLA having a current higher than that of a left pixelline area PLA and a right pixel line area PLA, which are adjacentthereto, and may determine the touch line area TLA corresponding to thecorresponding pixel line area PLA as a defective touch line area TLA inwhich the defective touch sensor TS is included.

For example, one touch block TB may include at least one of fourshort-circuit points SCP1, SCP2, SCP3 and SCP4 as shown in FIG. 15 . Thecurrent per pixel line areas PLA of the touch block TB may appear asshown in FIG. 16 . Referring to FIG. 16 , when one touch block TBincludes a first short-circuit point SCP1 (Short_1_0), a current of asecond pixel line area X2 may be higher than that of the other pixelline areas X1, X3,..., X12. When one touch block TB includes a secondshort-circuit point SCP2 (Short_0_1), a current of a sixth pixel linearea X6 may be higher than that of the other pixel line areas X1,...,X5, X7,..., X12. In addition, when one touch block TB includes thesecond short-circuit point SCP2 and a fourth short-circuit point SCP4(Short_0_2), the current of the sixth pixel line area X6 may be higherthan that of the other pixel line areas X1,..., X5, X7,..., X12, and maybe higher than the case that the short-circuit point is one. When onetouch block TB includes a third short-circuit point SCP3, the secondshort-circuit point SCP2 and the fourth short-circuit point SCP4(Short_1_2), the current of the second pixel line area X2 and the sixthpixel line area X6 may be higher than that of the other pixel line areasX1, X3, X4, X5, X7,..., X12.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the touch connection line TCL connected to the touchsensors TS included in the detected touch line area TLA may be cut by alaser, whereby the defective touch sensor TS and the touch bridge lineTBL may be electrically separated from each other. Therefore, thetransparent display panel 110 according to one embodiment of the presentdisclosure may allow the other touch sensors TS of the correspondingtouch block TB to operate normally.

In the transparent display panel 110 according to one embodiment of thepresent disclosure, the touch line area TLA in which the defective touchsensor TS is included may be easily detected in one touch block TB byusing the high resistance area of the cathode power area CPA. At thistime, in the transparent display panel 110 according to one embodimentof the present disclosure, luminance of the plurality of pixels P may besensed or the current per pixel line area PLA may be sensed through thepixel power line VDDL, and the touch line area TLA in which thedefective touch sensor TS is included may be detected using the sensedluminance or current. In the transparent display panel 110 according toone embodiment of the present disclosure, the high resistance area maybe implemented using the existing common power line VSSL or the existingcathode electrode CE. That is, in the transparent display panel 110according to one embodiment of the present disclosure, since a separatesignal line for sensing the voltage of the touch sensor TS is notadditionally provided, transmittance may be more improved than thestructure in which the voltage of the touch sensor TS is sensed using aseparate sensing line.

According to the present disclosure, the following advantageous effectsmay be obtained.

In the present disclosure, the touch sensor electrode of the touchsensor and the cathode electrode of the light emitting element may beformed using the first undercut structure at the same time, whereby thetouch process may be simplified, and a separate mask for the touchsensor electrode does not need to be additionally provided.

Also, in the present disclosure, the touch line area in which thedefective touch sensor is included may be easily detected in one touchblock by using the high resistance area of the cathode power area.

Also, in the present disclosure, the high resistance area may beimplemented using the existing common power line or the existing cathodeelectrode. That is, in the present disclosure, since a separate signalline for sensing the voltage of the touch sensor is not additionallyprovided, transmittance may be more improved than the structure in whichthe voltage of the touch sensor TS is sensed using a separate sensingline.

It will be apparent to those skilled in the art that the presentdisclosure described above is not limited by the above-describedembodiments and the accompanying drawings and that varioussubstitutions, modifications and variations can be made in the presentdisclosure without departing from the spirit or scope of thedisclosures. Consequently, the scope of the present disclosure isintended to cover all variations or modifications derived from themeaning, scope and equivalent concept described in the presentdisclosure.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments.

These and other changes can be made to the embodiments in light of theabove-detailed description. In general, in the following claims, theterms used should not be construed to limit the claims to the specificembodiments disclosed in the specification and the claims, but should beconstrued to include all possible embodiments along with the full scopeof equivalents to which such claims are entitled. Accordingly, theclaims are not limited by the disclosure.

1. A transparent display device with a touch sensor, the transparentdisplay device comprising: a substrate; a plurality of transmissiveareas and a non-transmissive area disposed between transmissive areasadjacent to each other on the substrate; a plurality of touch sensorsrespectively provided in the plurality of transmissive areas on thesubstrate, each touch sensor including a touch sensor electrode; aplurality of pixels disposed in the non-transmissive area on thesubstrate, each pixel including an anode electrode, a light emittinglayer, and a cathode electrode; a touch line extended in thenon-transmissive area in a first direction and electrically connected tothe touch sensor electrode; and a common power line electricallyconnected to the cathode electrode to supply a cathode power source,wherein the non-transmissive area includes a cathode power area to whichthe cathode power source is applied through the common power line,wherein the cathode power area includes a first cathode power areadisposed between the touch sensors adjacent to each other in a seconddirection and a second cathode power area disposed between the touchsensors adjacent to each other in the first direction, and wherein thesecond cathode power area has resistance higher than that of the firstcathode power area.
 2. The transparent display device of claim 1,wherein the second cathode power area has resistance of 1kΩ or more. 3.The transparent display device of claim 1, wherein the cathode electrodeincludes a first cathode electrode provided in the first cathode powerarea, having a first width, and a second cathode electrode provided inthe second cathode power area, having a second width smaller than thefirst width.
 4. The transparent display device of claim 3, wherein thesecond cathode electrode has resistance of 1 kΩ or more.
 5. Thetransparent display device of claim 3, wherein the second width of thesecond cathode electrode is smaller than 50 µm.
 6. The transparentdisplay device of claim 1, wherein the common power line includes afirst common power line provided in a first layer in the first cathodepower area and a second common power line provided in a second layer inthe second cathode power area.
 7. The transparent display device ofclaim 6, wherein the second common power line is made of a silicon-basedsemiconductor material or an oxide-based semiconductor material.
 8. Thetransparent display device of claim 6, wherein the second common powerline has resistance of 1 kΩ or more.
 9. The transparent display deviceof claim 6, wherein the first common power line is formed in a samelayer as one of a gate electrode, a source electrode, and a drainelectrode of a driving transistor, and wherein the second common powerline is provided in a same layer as an active layer of the drivingtransistor.
 10. The transparent display device of claim 1, furthercomprising a switching transistor electrically connecting or separatingthe common power line to or from a cathode power supply source.
 11. Thetransparent display device of claim 10, wherein the switching transistorseparates the common power line from the cathode power supply source inaccordance with a defect detection control signal and connects thecommon power line to the cathode power supply source in accordance witha general control signal.
 12. The transparent display device of claim 1,wherein the first cathode power area at least partially overlaps theplurality of pixels, and the second cathode power area does not overlapthe plurality of pixels.
 13. The transparent display device of claim 1,wherein the cathode electrode is disposed to be spaced apart from thetouch sensor electrode in a same layer as the touch sensor electrode.14. The transparent display device of claim 13, further comprising afirst undercut structure provided in the transmissive area, having aplanar closed shape, wherein the cathode electrode and the touch sensorelectrode are separated from each other by the first undercut structure.15. The transparent display device of claim 12, further comprising: aplurality of touch line areas in which the plurality of touch sensorsare disposed in a line in the first direction; a pixel power lineelectrically connected to the anode electrode; and a defect detectorcontrolling the pixel power line and the touch line to apply a firstvoltage and a second voltage to each of the pixel power line and thetouch line and determining a touch line area, in which a defective touchsensor is included, among the plurality of touch line areas based on acurrent or luminance of the plurality of pixels emitting light by acurrent generated between the pixel power line and the touch line. 16.The transparent display device of claim 15, wherein the pixel power lineis provided as a plurality of pixel power lines to correspond to theplurality of touch line areas one-to-one, and wherein the defectdetector senses a current per pixel line of the plurality of pixelsthrough the plurality of pixel power lines and determines a touch linearea corresponding to a pixel line having current higher than that of aleft pixel line and a right pixel line, which are adjacent thereto, as aline area in which the defective touch sensor is included.